ABSTRACT
In 1995 a new method of contraception, known as Mirena, was launched on the UK market. This product was developed by the Population Council and Leiras, a Finnish pharmaceutical company. Mirena is a Levonorgestrel-releasing intrauterine system (IUS). The development of the IUS has been a long process; the initial idea was considered in 1970. The process began with the development and production of a device which had a sleeve that released constant levels of the hormone Levonorgestrel over a long period of time. Mirena is also licensed for the treatment of primary menorrhagia which has relieved many women from horrendous menstrual problems when the only previous solution would have been a hysterectomy.
The intrauterine system (abbreviated to IUS) has a plastic T-shaped frame similar to a Nova T IUD but has a steroid reservoir around the vertical stem of the device containing the hormone Levonorgestrel. The device is 32mm in length and 4.8mm in diameter. It is inserted through the cervical canal into the uterus, where it sits releasing 20mcg of Levonorgestrel over 24 hours. Mirena is impregnated with barium sulphate which makes it radiopaque, and is licensed for fve years (see Fig. 12.1).
